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Related papers: Cosmic-ray driven dynamo in galaxies

200 papers

We discuss new methods to integrate the cosmic ray (CR) evolution equations coupled to magneto-hydrodynamics (MHD) on an unstructured moving mesh, as realised in the massively parallel AREPO code for cosmological simulations. We account for…

Astrophysics of Galaxies · Physics 2017-01-11 C. Pfrommer , R. Pakmor , K. Schaal , C. M. Simpson , V. Springel

We present simulations of the magnetized interstellar medium (ISM) in models of massive star forming (40 Msun / yr) disk galaxies with high gas surface densities (~100 Msun / pc^2) similar to observed star forming high-redshift disks. We…

Astrophysics of Galaxies · Physics 2015-06-17 Michal Hanasz , Harald Lesch , Thorsten Naab , Artur Gawryszczak , Kacper Kowalik , Dominik Wóltański

Observations show that the magnetic field in young supernova remnants (SNRs) is significantly stronger than can be expected from the compression of the circumstellar medium (CSM) by a factor of four expected for strong blast waves.…

Astrophysics of Galaxies · Physics 2009-08-05 K. M. Schure , J. Vink , A. Achterberg , R. Keppens

Galactic outflows influence the evolution of galaxies not only by expelling gas from their disks but also by injecting energy into the circumgalactic medium (CGM). This alters or even prevents the inflow of fresh gas onto the disk and thus…

Astrophysics of Galaxies · Physics 2025-06-04 Timon Thomas , Christoph Pfrommer , Rüdiger Pakmor

In the present paper we construct maps of polarized synchrotron radio emission of a whole galaxy, based on local models of the cosmic ray (CR) driven dynamo. We perform numerical simulations of the dynamo in local Cartesian domains, with…

We have calculated the cosmic ray (CR) acceleration at young remnants from Type Ia supernovae expanding into a uniform interstellar medium (ISM). Adopting quasi-parallel magnetic fields, gasdynamic equations and the diffusion convection…

Astrophysics · Physics 2008-11-26 Hyesung Kang

Cosmic-ray (CR) feedback is widely recognized as a key regulator of galaxy formation. After being accelerated at supernova remnant shocks, CRs propagate through the interstellar medium (ISM), establishing smooth large-scale distributions…

Astrophysics of Galaxies · Physics 2025-10-21 Timon Thomas , Christoph Pfrommer , Rüdiger Pakmor , Rouven Lemmerz , Mohamad Shalaby

We explore the impact of diffusive cosmic rays (CRs) on the evolution of the interstellar medium (ISM) under varying assumptions of supernova explosion environment. In practice, we systematically vary the relative fractions of supernovae…

Astrophysics of Galaxies · Physics 2022-12-28 Christine M. Simpson , Rüdiger Pakmor , Christoph Pfrommer , Simon C. O. Glover , Rowan Smith

Cosmic ray (CR) transport and acceleration is determined by the properties of magnetic turbulence. Recent advances in MHD turbulence call for revisions in the paradigm of cosmic ray transport. We use the models of magnetohydrodynamic…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Huirong Yan

Cosmic rays (CRs) are a plausible mechanism for launching winds of cool material from the discs of star-forming galaxies. However, there is no consensus on what types of galaxies likely host CR-driven winds, or what role these winds might…

Astrophysics of Galaxies · Physics 2021-03-03 Roland M. Crocker , Mark R. Krumholz , Todd A. Thompson

Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…

Astrophysics of Galaxies · Physics 2017-11-08 Michael Rieder , Romain Teyssier

The origin of cosmic rays (CRs) has puzzled scientists since the pioneering discovery by Victor Hess in 1912. In the last decade, however, modern supercomputers have opened a new window on the processes regulating astrophysical…

High Energy Astrophysical Phenomena · Physics 2015-11-27 Damiano Caprioli

Cosmic rays (CRs) and magnetic fields may be dynamically important in driving large-scale galactic outflows from rapidly star-forming galaxies. We construct two-dimensional axisymmetric models of the local starburst and super-wind galaxy…

Astrophysics of Galaxies · Physics 2020-04-29 Benjamin J. Buckman , Tim Linden , Todd A. Thompson

The physics of magnetic fields ($\textbf{B}$) and cosmic rays (CRs) have recently been included in simulations of galaxy formation. However, significant uncertainties remain in how these components affect galaxy evolution. To understand…

Cosmic ray (CR)-driven instabilities play a decisive role during particle acceleration at shocks and CR propagation in galaxies and galaxy clusters. These instabilities amplify magnetic fields and modulate CR transport so that the…

High Energy Astrophysical Phenomena · Physics 2021-03-03 Mohamad Shalaby , Timon Thomas , Christoph Pfrommer

Galactic-scale winds are a generic feature of massive galaxies with high star formation rates across a broad range of redshifts. Despite their importance, a detailed physical understanding of what drives these mass-loaded global flows has…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Munier Salem , Greg L. Bryan

We present a hydrodynamical simulation of the turbulent, magnetized, supernova (SN)-driven interstellar medium (ISM) in a stratified box that dynamically couples the injection and evolution of cosmic rays (CRs) and a self-consistent…

Galactic cosmic rays (CRs) are accelerated by astrophysical shocks, primarily supernova remnants (SNRs), via diffusive shock acceleration (DSA), an efficient mechanism that predicts power-law energy distributions of CRs. However,…

High Energy Astrophysical Phenomena · Physics 2021-09-24 Rebecca Diesing , Damiano Caprioli

It is shown that the nonlinear kinetic model of cosmic ray (CR) acceleration in supernova remnants (SNRs) fits the shell-type nonthermal X-ray morphology, obtained in Chandra observations, in a satisfactory way. The set of empirical…

Astrophysics · Physics 2007-05-23 E. G. Berezhko , L. T. Ksenofontov , H. J. Voelk

We analyse the transport of cosmic rays (CR) in magnetic fields that are structured on scales greater than the CR Larmor radius. We solve the Vlasov-Fokker-Planck (VFP) equation for various mixes of mirroring and small-angle scattering and…

High Energy Astrophysical Phenomena · Physics 2025-04-09 A. R. Bell , J. H. Matthews , A. M. Taylor , G. Giacinti